Selective signaling system.



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w. w. KInNE-Y. SELECTIVB SIGNALING SYSTEM.

APLIoATIoN FILED un as. 1907.

UNITED STATES WILLIAM W. IIDNEY, OF BUFFALO, NEW

PATENT YORK, AssIGNoR OFFICE.

TO CENTURY TELEPHONE CONSTRUCTION COMPANY, OF BUFFALO, NEW YORK, A CORPORATION OF NEW YORK.

SELECTIVE SIGNALIN' G SYSTEM.

To all whom it may concern:

Be it known that I, WILLIAM W. KIDNEY, a citizen in Selective Signaling Systems, of which the following is a specification.

My invention relates to improvements in selective signaling systems for telephone lines, and has for its embodying my Figure I is a diagrammatic view oi one oi such systems or central office; and Fig. II is a small or two-party line employing an all-metallic circuit both for a talking and signaling currents.

For easy reference and in may be avoided,

both figures of the drawings.

In each of these ligures A is assumed to be the central proper polarity, directed over either limb of the line for actuating suitable polarized signaling bells respectively positioned at the dilerent stations.

Speccation of Letters Patent. Application filed May 28, 1907.

Patented Aug. 20, 1907. serial No. 376,055.

Referring now to Fig. tion of my invention, I may point out that the signaling battery is subdivided into two sections B B, respectively having their positive and negative poles with a third conductor. A single battery may be employed, as in Fig. II, instead but only with attendant complicathat a siggenerating approximately 130 volts, is preferable in association with ordinary telephone lines. The battery extends by suitable leads a/, a, to the spring contacts of the selective signaling keys b, c, d, e, corresponding to the several selective stations signaled. The usual accessories of a cord circuit are provided, of which p p are respectively the calling and answering plugs, s sf, the supervisory signals, and o, the operators telephone set. At j is shown the spring jack switch forming the terminal of the partyline under consideration, of which Z is the line signal.

At the several sub-stations is provided the usual telebells, adapted to respond either to currents of positive or negative polarity;

circuit opening and closing device actuated by the arcurrents of negative polarity, while stations C and E are adapted to be signaled by currents of positive polarity, as indicated by the plus and minus signs applied thereto'.

Assuming now that station B is to be selectively signaled, the key b is depressed, thereby directing current from battery B over conductor a, springs l and 5, which will be closed, to the tip 6 of plug 7o, now assumed to be inserted in the spring jack j, line spring 7, the switch hook of the bell, conductor l2, transposition-contacts 13, 14, windings l5 of said bell, transposition-contacts 1G, 17 to the condenser 18, Which .is immediately charged. The bell armature is thereby actuated in the charging of the condenser to open the contacts I0, ll and close contacts l1, I9, thereby giving the irst tap upon the bell. Upon the closure said bells being provided with a y I for a more specific explanais sounded upon the bell. This oscillation of the armature with the attendant signaling of station B and the discharging of the condenser, continues as long as key b is held depressed by the operator. The station C also connected with limb a of the line, is not actuated by these currents for the reason that it is responsive to positive currents, and its transposition contacts are connected between 13, 16 and 14, 17. Accordingly, upon the depression of key c instead, positive currents would have been directed over limb a of the line and actuated the bell at station G in precisely the same manner described above. Similarly the actuation of key d would have directed negative current over limb x o the line, thereby actuating the bell at station D charging the condenser 38, opening the contacts 30, 31, and closing the contacts 31, 39, whereby the signaling cycle is accomplished as before described'.

lnasmuch as the condenser is momentarily disconnected from the line by the altered condition oi the bell contacts, during the instant of discharge, and is short circuited through the bell windings, the system is freed from the diiliculty which would arise by reason of the possibility otherwise of transmitting a false signal to the line. Said condenser is made of sufiiciently large capacity to insure a charge which shall act upon the bell windings, as 15 or 35, and insure the immediate reversal of the armatures position with an attendant alteration of circuit conditions at the sub-station.

In both of the figures of the drawings, the arrangements are so similar as to require but little further description. Battery B2 in both systems is here shown as a separate battery for the talking circuit, while battery B/ alone is used in Fig. 11 for signaling7 inasmuch as no complications are encountered rendering a reversing switch necessary. As before, we may assume that station B, which with station C is connected directly between the limbs oi the metallic circuit a x, is adapted to be selected or rung by negative currents. Upon the depression oi key b accordingly, current will be transmitted from battery B through the cord circuit and over limb a oi the line, through the switch hook and its contact 8, 9, closed contacts 10, 1l, conductor 12, transposition contacts 13, 14, the bell windings 15, transposition contacts 16, 17 and to condenser 18, thereby charging the same. Contact 19 in this instance is connected to limb x of the line which during the insertion of the-plug is in turn connected through the cord circuit to the positive pole of battery Bf. The actuation oi the contact 11 into engagement with contact 19, the discharge oi the condenser and the actuation of the bell will all result as before described.

From the foregoing it will be appreciated that a thoroughly satisfactory system is provided, whereby the various stations may be selectively signaled by means of a battery or other suitable source of current provided at the central office. By reason oi the employment of a condenser with suitable make-and-brealr apparatus connected as shown, the selective actuation of the bells is materially augmented or improved and ialse signaling currents are prevented irom being transmitted to the associated bells.

1t will be well understood, of course, that the number of sub-stations may be varied or may be increased upon a given line by employing partial selection, and a code of signals. Other modifications than those herein reierred to will occur Ato those skilled in the art, which I desire to secure for myself in accordance with the following claims.

1. In a' selective signaling system, the combination with a source of signaling current, switching mechanism for applying such current of requisite polarity to the line, a line or signaling circuit, and a plurality of substations connected thereto, each equipped with polarized signaling apparatus, a condenser' and means for opening and closing the circuit to the condenser, substantially as set forth.

2. In a selective signaling system, the combination with a source of signaling current, switching mechanism for applying such current of requisite polarity to the line, a line or signaling circuit, and a plurality of substations connected thereto, each equipped with polarized signaling apparatus normally connected to line, an associated condenser, and means for opening the circuit of the condenser and 'causing its discharge through the signaling apparatus, substantially as set forth.

3.1n a selective signaling system, the combination with a source of signaling current, switching mechanism for applying such current of requisite polarity to the line, a line or signaling circuit, and a plurality of substations connected thereto, cach equipped with a polarized signaling bell normally connected to line and with one side of an associated condenser, the other side of said condenser being connected with a return conductor, and a switch actuated by the bell momentarily to open the circuit to the line and close the condenser circuit through the windings of said bell, substantially as set forth.

4. In a telephone signaling system, the combination with a signaling battery at the central oiiice, switchingmechanism adapted to connect the same to line in a manner to insure currents of definite polarity, a telephone line forming the signaling circuit, and a plurality of stations normally connected to line; each of said stations being equipped with telephone apparatus, a polarized signaling bell normally connected to line and to one side of an associated condenser, the other side of said condenser being connected to a return conductor, and switch contacts respectively controlling the circuit to the bell and return conductor alternatively engaged to effect the actuation of said bell, substantially as set forth.

5. ln a selective signaling circuit connecting a central station with a plurality of sub-stations, and comprising two main or line conductors and a third conductor, branch circuits extending from each of said line conductors to the third conductor, a polarized bell and a condenser normally connected serially in each of said branch conductors, and a make-and-break device controlling the circuit to each of said bells and automaticallyactuated upon the operation of the associated bell, a source of signaling current at the central oice, and switching keys for applying currents of appropriate polarity to either of the main or line conductors, substantially as set forth.

G. In a telephone system, the combination with telephone line conductors extending from an exchange to a plurality of telephone sub-stations, of a plurality of positively and negatively polarized bells and associated condensers normally connected therewith at the several substations, automatically actuated means controlled by the bells for respectively opening their circuits and ettecting the discharge of their condensers, and means at the central oflice for applying current of positive or negative polarity to the line conductors, substantially as set forth.

7. ln a selective signaling telephone system, the combination with a battery at the central office, switching mechanism controlling the same, a telephone circuit comtemporarily to be associated with said battery, a plurality of telephone substations respectively connected between the line conductors and the third conductor, 'and at each of said stations a polarized signaling bell normally polarized bell and the third conductor, whereby said bell is adapted for actuation by currents of appropriate polar'- ity, substantially as set forth.

prising two line conductors and a third conductor adapted 1- connected to line, an automatic circuit controlling device l actuated thereby, and a condenser' connected between the S. In a telephone signaling system, the combination with a source of direct current, switching mechanism adapted to apply the saine to an associated telephone line, two telephone each being equipped with a polarized bell normally connected to a line conductor, a serially connected condenser and a circuit controlling device actuated by the bell and adapted to disconnect it from the line and short circuit thecondenser through the bell windings, substantially as set forth..

Signed at Budalo, this 18th day of May, A. D., 1907 in the presence of two subscribing witnesses.

WILLIAM W. KIDNEY. Witnesses:

HARRY A. HATHAWAY, BURTON W. SWEET. 

